Pocky! (Special offer)
Pocky is one of my
favourite snacks. I just went and got a box from the Chinese grocery nearby, as I wanted to check something out.

On the back of the box is one of these:

It's a
QR Code. The basic idea is, after you've finished eating your Pocky you take a photo of the QR Code with your phone and send it to a website. Software on the website recognises the code and then sends you a reply SMS with a "special offer" or a "free gift". Of course, it doesn't just have to be like that - you could also use it send people info about a statue they were looking at, or timetable info, or news, or anything really.